Checking with my peers, the key error in your extract should be the following:
IPP ERROR: Application exception: System.IO.InvalidDataException: CMS signature blob size is too large for the allocated size, unable to create useful code signing data
This issue refers to a recent conflict between UE’s IPhonePackager and the latest versions of Xcode, as it’s signature has changed to a larger structure. When UE attempts to read the format, it can’t handle the larger signature blobs, resulting in a crash.
The solution here would be to roll back your update, and go back to the previous version of Xcode you were using, until a hotfix is deployed on Epic’s end. And once you do the downgrade, please ensure that your cache’s project is cleared, either by using “Clean Build Folder”, or manually deleting folder “DerivedData”.
am attep to use the macos26 and old xcode16.2 with the same situation.
cd /Users/oooo/UE5/Builds/PC-2025RLHYJB/D/D:/Intermediate/ProjectFilesIOS
/Applications/Xcode.app/Contents/Developer/usr/bin/actool --output-format human-readable-text --notices --warnings --export-dependency-info
/* com.apple.actool.errors /
/Users/oooo/UE5/Builds/PC-2025RLHYJB/D/D:/UnrealEngine/Engine/Build/IOS/Resources/Assets.xcassets: error: Failed to launch AssetCatalogSimulatorAgent via CoreSimulator spawn
Underlying Errors:
Description: Failed to handshake with platform tool
Failure Reason: Failed to open connection over FIFOs with platform tool
Underlying Errors:
Description:
Recovery Suggestion: Try restarting your computer
Underlying Errors:
Description: Failed to open FIFOs for handshaking with platform tool
Failure Reason: AssetCatalogSimulatorAgent exited before we could handshake
/ com.apple.actool.compilation-results */
Revision: 5f30d8f91dee499ab2576d65dd5dd2025b8127ba
Author: stephane jacoby stephane.jacoby@epicgames.com
Date: 2025/11/6 2:17:29
Message:
In remote iOS build, ensure that Provision Profiles folder is created prior to installing the Windows specified provisioning profile on the remote mac.
Work around new MacOS 26 codesigning CMS blob size errors by no longer enforcing that replacement signature on Windows be done in place of the one generated on MacOS as the size of these no longer match. This involves restoring the old code that was offsetting the __LINKEDIT section to accomodate changes in the size of the LC_CODE_SIGNATURE section.